Same here with Mojave. 2015 iMac Retina 5k 27" using a UAD Apollo Twin Thunderbolt. Spinning beach-ball for almost every thing I select. Like changing a patch in a VST instrument takes about 5-20 seconds. Moving a slider or knob in almost every VST creates a spinning beach-ball. Changing a VST to a different VST basically creates a 2-5 minute long spinning beach-ball with “application not responding” when I right click the Cubase 10.5 icon so I can exit the fricken program. Super frustrated!!! : (
I’m currently downloading the full 21.90GB installer to see if maybe the 1.50GB update installer is part of the problem. Sometimes a clean install helps but in this case I’m thinking that maybe Steinberg adding new code to code from the past 20+ years is starting to bite everyone in the ass.